Coal can be efficiently converted into hydrocarbons of a more useful gaseous or liquid form by coal gasification or liquefaction techniques, utilizing energy from a high-temperature, gas-cooled nuclear reactor for the endothermic and/or electrolytic processing required, as taught by Jones, in U.S. Pat. No. 4,158,673. While the United States, the Soviet Union, and China still contain major deposits of coal, this mineral is considered precious in most other parts of the world, where deposits are either lacking or have been largely used up.
Thus, while the earth's supply of precious fossil fuels is being steadily depleted to provide electricity and petrochemicals, a virtually unlimited worldwide supply of other carbon bearing minerals remains untapped as an energy source. Salotti, in U.S. Pat. No. 3,558,724, taught that inorganic crystalline carbonates could provide gaseous products containing up to 4% methane, if the carbonates were first heated in an oxygen-free atmosphere at from about 400.degree. C. to 700.degree. C., and then contacted with excess hydrogen gas at from about 200 psi. to 10,000 psi. This process, however, uses large quantities of valuable hydrogen gas, which is becoming increasingly important itself as an energy source. In addition, this process provides a poor yield of methane, leaves carbon residue and maintains explosive reaction conditions.
Tamers, in U.S. Pat. No. 4,009,219, taught the production of benzene from inorganic carbonates such as limestone. Tamers reacted limestone (CaCO.sub.3) with lithium metal in a vacuum at 500.degree. C., raised the temperature of reaction to 1,000.degree. C. for 30 minutes to reverse secondary reactions that produce carbon and metal oxide, and then hydrolyzed the resulting product lithium carbide (Li.sub.2 C.sub.2) with water. This produced acetylene, with calcium oxide and lithium hydroxide by-products. The lithium hydroxide was converted to lithium metal by fused salt electrolysis, and recycled back to the limestone reaction. The acetylene was then purified and dried. Benzene was produced from this treated acetylene, using dried potassium chromate activated silica-alumina catalyst at 120.degree. C. to 200.degree. C. Benzene, however, is now known to be toxic and a carcinogenic agent.
What is needed is a method to produce high carbon chain hydrocarbons without using valuable fuels such as coal or hydrogen or producing toxic substances such as benzene.